mac80211.c

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/******************************************************************************
 *
 * Copyright(c) 2003 - 2012 Intel Corporation. All rights reserved.
 *
 * Portions of this file are derived from the ipw3945 project, as well
 * as portions of the ieee80211 subsystem header files.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
 *
 * The full GNU General Public License is included in this distribution in the
 * file called LICENSE.
 *
 * Contact Information:
 *  Intel Linux Wireless <[email protected]>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 *****************************************************************************/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>

#include <net/ieee80211_radiotap.h>
#include <net/mac80211.h>

#include <asm/div64.h>

#include "iwl-io.h"
#include "iwl-trans.h"
#include "iwl-op-mode.h"
#include "iwl-modparams.h"

#include "dev.h"
#include "calib.h"
#include "agn.h"

/*****************************************************************************
 *
 * mac80211 entry point functions
 *
 *****************************************************************************/

static const struct ieee80211_iface_limit iwlagn_sta_ap_limits[] = {
    {
        .max = 1,
        .types = BIT(NL80211_IFTYPE_STATION),
    },
    {
        .max = 1,
        .types = BIT(NL80211_IFTYPE_AP),
    },
};

static const struct ieee80211_iface_limit iwlagn_2sta_limits[] = {
    {
        .max = 2,
        .types = BIT(NL80211_IFTYPE_STATION),
    },
};

static const struct ieee80211_iface_limit iwlagn_p2p_sta_go_limits[] = {
    {
        .max = 1,
        .types = BIT(NL80211_IFTYPE_STATION),
    },
    {
        .max = 1,
        .types = BIT(NL80211_IFTYPE_P2P_GO) |
             BIT(NL80211_IFTYPE_AP),
    },
};

static const struct ieee80211_iface_limit iwlagn_p2p_2sta_limits[] = {
    {
        .max = 2,
        .types = BIT(NL80211_IFTYPE_STATION),
    },
    {
        .max = 1,
        .types = BIT(NL80211_IFTYPE_P2P_CLIENT),
    },
};

static const struct ieee80211_iface_combination
iwlagn_iface_combinations_dualmode[] = {
    { .num_different_channels = 1,
      .max_interfaces = 2,
      .beacon_int_infra_match = true,
      .limits = iwlagn_sta_ap_limits,
      .n_limits = ARRAY_SIZE(iwlagn_sta_ap_limits),
    },
    { .num_different_channels = 1,
      .max_interfaces = 2,
      .limits = iwlagn_2sta_limits,
      .n_limits = ARRAY_SIZE(iwlagn_2sta_limits),
    },
};

static const struct ieee80211_iface_combination
iwlagn_iface_combinations_p2p[] = {
    { .num_different_channels = 1,
      .max_interfaces = 2,
      .beacon_int_infra_match = true,
      .limits = iwlagn_p2p_sta_go_limits,
      .n_limits = ARRAY_SIZE(iwlagn_p2p_sta_go_limits),
    },
    { .num_different_channels = 1,
      .max_interfaces = 2,
      .limits = iwlagn_p2p_2sta_limits,
      .n_limits = ARRAY_SIZE(iwlagn_p2p_2sta_limits),
    },
};

/*
 * Not a mac80211 entry point function, but it fits in with all the
 * other mac80211 functions grouped here.
 */
int iwlagn_mac_setup_register(struct iwl_priv *priv,
                  const struct iwl_ucode_capabilities *capa)
{
    int ret;
    struct ieee80211_hw *hw = priv->hw;
    struct iwl_rxon_context *ctx;

    hw->rate_control_algorithm = "iwl-agn-rs";

    /* Tell mac80211 our characteristics */
    hw->flags = IEEE80211_HW_SIGNAL_DBM |
            IEEE80211_HW_AMPDU_AGGREGATION |
            IEEE80211_HW_NEED_DTIM_PERIOD |
            IEEE80211_HW_SPECTRUM_MGMT |
            IEEE80211_HW_REPORTS_TX_ACK_STATUS |
            IEEE80211_HW_QUEUE_CONTROL |
            IEEE80211_HW_SUPPORTS_PS |
            IEEE80211_HW_SUPPORTS_DYNAMIC_PS |
            IEEE80211_HW_WANT_MONITOR_VIF |
            IEEE80211_HW_SCAN_WHILE_IDLE;

    hw->offchannel_tx_hw_queue = IWL_AUX_QUEUE;
    hw->radiotap_mcs_details |= IEEE80211_RADIOTAP_MCS_HAVE_FMT;

    /*
     * Including the following line will crash some AP's.  This
     * workaround removes the stimulus which causes the crash until
     * the AP software can be fixed.
    hw->max_tx_aggregation_subframes = LINK_QUAL_AGG_FRAME_LIMIT_DEF;
     */

    if (priv->eeprom_data->sku & EEPROM_SKU_CAP_11N_ENABLE)
        hw->flags |= IEEE80211_HW_SUPPORTS_DYNAMIC_SMPS |
                 IEEE80211_HW_SUPPORTS_STATIC_SMPS;

#ifndef CONFIG_IWLWIFI_EXPERIMENTAL_MFP
    /* enable 11w if the uCode advertise */
    if (capa->flags & IWL_UCODE_TLV_FLAGS_MFP)
#endif /* !CONFIG_IWLWIFI_EXPERIMENTAL_MFP */
        hw->flags |= IEEE80211_HW_MFP_CAPABLE;

    hw->sta_data_size = sizeof(struct iwl_station_priv);
    hw->vif_data_size = sizeof(struct iwl_vif_priv);

    for_each_context(priv, ctx) {
        hw->wiphy->interface_modes |= ctx->interface_modes;
        hw->wiphy->interface_modes |= ctx->exclusive_interface_modes;
    }

    BUILD_BUG_ON(NUM_IWL_RXON_CTX != 2);

    if (hw->wiphy->interface_modes & BIT(NL80211_IFTYPE_P2P_CLIENT)) {
        hw->wiphy->iface_combinations = iwlagn_iface_combinations_p2p;
        hw->wiphy->n_iface_combinations =
            ARRAY_SIZE(iwlagn_iface_combinations_p2p);
    } else if (hw->wiphy->interface_modes & BIT(NL80211_IFTYPE_AP)) {
        hw->wiphy->iface_combinations =
            iwlagn_iface_combinations_dualmode;
        hw->wiphy->n_iface_combinations =
            ARRAY_SIZE(iwlagn_iface_combinations_dualmode);
    }

    hw->wiphy->max_remain_on_channel_duration = 500;

    hw->wiphy->flags |= WIPHY_FLAG_CUSTOM_REGULATORY |
                WIPHY_FLAG_DISABLE_BEACON_HINTS |
                WIPHY_FLAG_IBSS_RSN;

#ifdef CONFIG_PM_SLEEP
    if (priv->fw->img[IWL_UCODE_WOWLAN].sec[0].len &&
        priv->trans->ops->wowlan_suspend &&
        device_can_wakeup(priv->trans->dev)) {
        hw->wiphy->wowlan.flags = WIPHY_WOWLAN_MAGIC_PKT |
                      WIPHY_WOWLAN_DISCONNECT |
                      WIPHY_WOWLAN_EAP_IDENTITY_REQ |
                      WIPHY_WOWLAN_RFKILL_RELEASE;
        if (!iwlwifi_mod_params.sw_crypto)
            hw->wiphy->wowlan.flags |=
                WIPHY_WOWLAN_SUPPORTS_GTK_REKEY |
                WIPHY_WOWLAN_GTK_REKEY_FAILURE;

        hw->wiphy->wowlan.n_patterns = IWLAGN_WOWLAN_MAX_PATTERNS;
        hw->wiphy->wowlan.pattern_min_len =
                    IWLAGN_WOWLAN_MIN_PATTERN_LEN;
        hw->wiphy->wowlan.pattern_max_len =
                    IWLAGN_WOWLAN_MAX_PATTERN_LEN;
    }
#endif

    if (iwlwifi_mod_params.power_save)
        hw->wiphy->flags |= WIPHY_FLAG_PS_ON_BY_DEFAULT;
    else
        hw->wiphy->flags &= ~WIPHY_FLAG_PS_ON_BY_DEFAULT;

    hw->wiphy->max_scan_ssids = PROBE_OPTION_MAX;
    /* we create the 802.11 header and a max-length SSID element */
    hw->wiphy->max_scan_ie_len = capa->max_probe_length - 24 - 34;

    /*
     * We don't use all queues: 4 and 9 are unused and any
     * aggregation queue gets mapped down to the AC queue.
     */
    hw->queues = IWLAGN_FIRST_AMPDU_QUEUE;

    hw->max_listen_interval = IWL_CONN_MAX_LISTEN_INTERVAL;

    if (priv->eeprom_data->bands[IEEE80211_BAND_2GHZ].n_channels)
        priv->hw->wiphy->bands[IEEE80211_BAND_2GHZ] =
            &priv->eeprom_data->bands[IEEE80211_BAND_2GHZ];
    if (priv->eeprom_data->bands[IEEE80211_BAND_5GHZ].n_channels)
        priv->hw->wiphy->bands[IEEE80211_BAND_5GHZ] =
            &priv->eeprom_data->bands[IEEE80211_BAND_5GHZ];

    hw->wiphy->hw_version = priv->trans->hw_id;

    iwl_leds_init(priv);

    ret = ieee80211_register_hw(priv->hw);
    if (ret) {
        IWL_ERR(priv, "Failed to register hw (error %d)\n", ret);
        iwl_leds_exit(priv);
        return ret;
    }
    priv->mac80211_registered = 1;

    return 0;
}

void iwlagn_mac_unregister(struct iwl_priv *priv)
{
    if (!priv->mac80211_registered)
        return;
    iwl_leds_exit(priv);
    ieee80211_unregister_hw(priv->hw);
    priv->mac80211_registered = 0;
}

static int __iwl_up(struct iwl_priv *priv)
{
    struct iwl_rxon_context *ctx;
    int ret;

    lockdep_assert_held(&priv->mutex);

    if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
        IWL_WARN(priv, "Exit pending; will not bring the NIC up\n");
        return -EIO;
    }

    for_each_context(priv, ctx) {
        ret = iwlagn_alloc_bcast_station(priv, ctx);
        if (ret) {
            iwl_dealloc_bcast_stations(priv);
            return ret;
        }
    }

    ret = iwl_run_init_ucode(priv);
    if (ret) {
        IWL_ERR(priv, "Failed to run INIT ucode: %d\n", ret);
        goto error;
    }

    ret = iwl_load_ucode_wait_alive(priv, IWL_UCODE_REGULAR);
    if (ret) {
        IWL_ERR(priv, "Failed to start RT ucode: %d\n", ret);
        goto error;
    }

    ret = iwl_alive_start(priv);
    if (ret)
        goto error;
    return 0;

 error:
    set_bit(STATUS_EXIT_PENDING, &priv->status);
    iwl_down(priv);
    clear_bit(STATUS_EXIT_PENDING, &priv->status);

    IWL_ERR(priv, "Unable to initialize device.\n");
    return ret;
}

static int iwlagn_mac_start(struct ieee80211_hw *hw)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    int ret;

    IWL_DEBUG_MAC80211(priv, "enter\n");

    /* we should be verifying the device is ready to be opened */
    mutex_lock(&priv->mutex);
    ret = __iwl_up(priv);
    mutex_unlock(&priv->mutex);
    if (ret)
        return ret;

    IWL_DEBUG_INFO(priv, "Start UP work done.\n");

    /* Now we should be done, and the READY bit should be set. */
    if (WARN_ON(!test_bit(STATUS_READY, &priv->status)))
        ret = -EIO;

    iwlagn_led_enable(priv);

    priv->is_open = 1;
    IWL_DEBUG_MAC80211(priv, "leave\n");
    return 0;
}

static void iwlagn_mac_stop(struct ieee80211_hw *hw)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);

    IWL_DEBUG_MAC80211(priv, "enter\n");

    if (!priv->is_open)
        return;

    priv->is_open = 0;

    mutex_lock(&priv->mutex);
    iwl_down(priv);
    mutex_unlock(&priv->mutex);

    iwl_cancel_deferred_work(priv);

    flush_workqueue(priv->workqueue);

    /* User space software may expect getting rfkill changes
     * even if interface is down, trans->down will leave the RF
     * kill interrupt enabled
     */
    iwl_trans_stop_hw(priv->trans, false);

    IWL_DEBUG_MAC80211(priv, "leave\n");
}

static void iwlagn_mac_set_rekey_data(struct ieee80211_hw *hw,
                      struct ieee80211_vif *vif,
                      struct cfg80211_gtk_rekey_data *data)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);

    if (iwlwifi_mod_params.sw_crypto)
        return;

    IWL_DEBUG_MAC80211(priv, "enter\n");
    mutex_lock(&priv->mutex);

    if (priv->contexts[IWL_RXON_CTX_BSS].vif != vif)
        goto out;

    memcpy(priv->kek, data->kek, NL80211_KEK_LEN);
    memcpy(priv->kck, data->kck, NL80211_KCK_LEN);
    priv->replay_ctr =
        cpu_to_le64(be64_to_cpup((__be64 *)&data->replay_ctr));
    priv->have_rekey_data = true;

 out:
    mutex_unlock(&priv->mutex);
    IWL_DEBUG_MAC80211(priv, "leave\n");
}

#ifdef CONFIG_PM_SLEEP

static int iwlagn_mac_suspend(struct ieee80211_hw *hw,
                  struct cfg80211_wowlan *wowlan)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
    int ret;

    if (WARN_ON(!wowlan))
        return -EINVAL;

    IWL_DEBUG_MAC80211(priv, "enter\n");
    mutex_lock(&priv->mutex);

    /* Don't attempt WoWLAN when not associated, tear down instead. */
    if (!ctx->vif || ctx->vif->type != NL80211_IFTYPE_STATION ||
        !iwl_is_associated_ctx(ctx)) {
        ret = 1;
        goto out;
    }

    ret = iwlagn_suspend(priv, wowlan);
    if (ret)
        goto error;

    iwl_trans_wowlan_suspend(priv->trans);

    goto out;

 error:
    priv->wowlan = false;
    iwlagn_prepare_restart(priv);
    ieee80211_restart_hw(priv->hw);
 out:
    mutex_unlock(&priv->mutex);
    IWL_DEBUG_MAC80211(priv, "leave\n");

    return ret;
}

static int iwlagn_mac_resume(struct ieee80211_hw *hw)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
    struct ieee80211_vif *vif;
    unsigned long flags;
    u32 base, status = 0xffffffff;
    int ret = -EIO;

    IWL_DEBUG_MAC80211(priv, "enter\n");
    mutex_lock(&priv->mutex);

    iwl_write32(priv->trans, CSR_UCODE_DRV_GP1_CLR,
              CSR_UCODE_DRV_GP1_BIT_D3_CFG_COMPLETE);

    base = priv->device_pointers.error_event_table;
    if (iwlagn_hw_valid_rtc_data_addr(base)) {
        spin_lock_irqsave(&priv->trans->reg_lock, flags);
        ret = iwl_grab_nic_access_silent(priv->trans);
        if (likely(ret == 0)) {
            iwl_write32(priv->trans, HBUS_TARG_MEM_RADDR, base);
            status = iwl_read32(priv->trans, HBUS_TARG_MEM_RDAT);
            iwl_release_nic_access(priv->trans);
        }
        spin_unlock_irqrestore(&priv->trans->reg_lock, flags);

#ifdef CONFIG_IWLWIFI_DEBUGFS
        if (ret == 0) {
            const struct fw_img *img;

            img = &(priv->fw->img[IWL_UCODE_WOWLAN]);
            if (!priv->wowlan_sram) {
                priv->wowlan_sram =
                   kzalloc(img->sec[IWL_UCODE_SECTION_DATA].len,
                        GFP_KERNEL);
            }

            if (priv->wowlan_sram)
                _iwl_read_targ_mem_dwords(
                      priv->trans, 0x800000,
                      priv->wowlan_sram,
                      img->sec[IWL_UCODE_SECTION_DATA].len / 4);
        }
#endif
    }

    /* we'll clear ctx->vif during iwlagn_prepare_restart() */
    vif = ctx->vif;

    priv->wowlan = false;

    iwlagn_prepare_restart(priv);

    memset((void *)&ctx->active, 0, sizeof(ctx->active));
    iwl_connection_init_rx_config(priv, ctx);
    iwlagn_set_rxon_chain(priv, ctx);

    mutex_unlock(&priv->mutex);
    IWL_DEBUG_MAC80211(priv, "leave\n");

    ieee80211_resume_disconnect(vif);

    return 1;
}

static void iwlagn_mac_set_wakeup(struct ieee80211_hw *hw, bool enabled)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);

    device_set_wakeup_enable(priv->trans->dev, enabled);
}
#endif

static void iwlagn_mac_tx(struct ieee80211_hw *hw,
              struct ieee80211_tx_control *control,
              struct sk_buff *skb)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);

    IWL_DEBUG_TX(priv, "dev->xmit(%d bytes) at rate 0x%02x\n", skb->len,
             ieee80211_get_tx_rate(hw, IEEE80211_SKB_CB(skb))->bitrate);

    if (iwlagn_tx_skb(priv, control->sta, skb))
        ieee80211_free_txskb(hw, skb);
}

static void iwlagn_mac_update_tkip_key(struct ieee80211_hw *hw,
                       struct ieee80211_vif *vif,
                       struct ieee80211_key_conf *keyconf,
                       struct ieee80211_sta *sta,
                       u32 iv32, u16 *phase1key)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);

    iwl_update_tkip_key(priv, vif, keyconf, sta, iv32, phase1key);
}

static int iwlagn_mac_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
                  struct ieee80211_vif *vif,
                  struct ieee80211_sta *sta,
                  struct ieee80211_key_conf *key)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    struct iwl_vif_priv *vif_priv = (void *)vif->drv_priv;
    struct iwl_rxon_context *ctx = vif_priv->ctx;
    int ret;
    bool is_default_wep_key = false;

    IWL_DEBUG_MAC80211(priv, "enter\n");

    if (iwlwifi_mod_params.sw_crypto) {
        IWL_DEBUG_MAC80211(priv, "leave - hwcrypto disabled\n");
        return -EOPNOTSUPP;
    }

    switch (key->cipher) {
    case WLAN_CIPHER_SUITE_TKIP:
        key->flags |= IEEE80211_KEY_FLAG_GENERATE_MMIC;
        /* fall through */
    case WLAN_CIPHER_SUITE_CCMP:
        key->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
        break;
    default:
        break;
    }

    /*
     * We could program these keys into the hardware as well, but we
     * don't expect much multicast traffic in IBSS and having keys
     * for more stations is probably more useful.
     *
     * Mark key TX-only and return 0.
     */
    if (vif->type == NL80211_IFTYPE_ADHOC &&
        !(key->flags & IEEE80211_KEY_FLAG_PAIRWISE)) {
        key->hw_key_idx = WEP_INVALID_OFFSET;
        return 0;
    }

    /* If they key was TX-only, accept deletion */
    if (cmd == DISABLE_KEY && key->hw_key_idx == WEP_INVALID_OFFSET)
        return 0;

    mutex_lock(&priv->mutex);
    iwl_scan_cancel_timeout(priv, 100);

    BUILD_BUG_ON(WEP_INVALID_OFFSET == IWLAGN_HW_KEY_DEFAULT);

    /*
     * If we are getting WEP group key and we didn't receive any key mapping
     * so far, we are in legacy wep mode (group key only), otherwise we are
     * in 1X mode.
     * In legacy wep mode, we use another host command to the uCode.
     */
    if ((key->cipher == WLAN_CIPHER_SUITE_WEP40 ||
         key->cipher == WLAN_CIPHER_SUITE_WEP104) && !sta) {
        if (cmd == SET_KEY)
            is_default_wep_key = !ctx->key_mapping_keys;
        else
            is_default_wep_key =
                key->hw_key_idx == IWLAGN_HW_KEY_DEFAULT;
    }


    switch (cmd) {
    case SET_KEY:
        if (is_default_wep_key) {
            ret = iwl_set_default_wep_key(priv, vif_priv->ctx, key);
            break;
        }
        ret = iwl_set_dynamic_key(priv, vif_priv->ctx, key, sta);
        if (ret) {
            /*
             * can't add key for RX, but we don't need it
             * in the device for TX so still return 0
             */
            ret = 0;
            key->hw_key_idx = WEP_INVALID_OFFSET;
        }

        IWL_DEBUG_MAC80211(priv, "enable hwcrypto key\n");
        break;
    case DISABLE_KEY:
        if (is_default_wep_key)
            ret = iwl_remove_default_wep_key(priv, ctx, key);
        else
            ret = iwl_remove_dynamic_key(priv, ctx, key, sta);

        IWL_DEBUG_MAC80211(priv, "disable hwcrypto key\n");
        break;
    default:
        ret = -EINVAL;
    }

    mutex_unlock(&priv->mutex);
    IWL_DEBUG_MAC80211(priv, "leave\n");

    return ret;
}

static int iwlagn_mac_ampdu_action(struct ieee80211_hw *hw,
                   struct ieee80211_vif *vif,
                   enum ieee80211_ampdu_mlme_action action,
                   struct ieee80211_sta *sta, u16 tid, u16 *ssn,
                   u8 buf_size)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    int ret = -EINVAL;
    struct iwl_station_priv *sta_priv = (void *) sta->drv_priv;

    IWL_DEBUG_HT(priv, "A-MPDU action on addr %pM tid %d\n",
             sta->addr, tid);

    if (!(priv->eeprom_data->sku & EEPROM_SKU_CAP_11N_ENABLE))
        return -EACCES;

    IWL_DEBUG_MAC80211(priv, "enter\n");
    mutex_lock(&priv->mutex);

    switch (action) {
    case IEEE80211_AMPDU_RX_START:
        if (iwlwifi_mod_params.disable_11n & IWL_DISABLE_HT_RXAGG)
            break;
        IWL_DEBUG_HT(priv, "start Rx\n");
        ret = iwl_sta_rx_agg_start(priv, sta, tid, *ssn);
        break;
    case IEEE80211_AMPDU_RX_STOP:
        IWL_DEBUG_HT(priv, "stop Rx\n");
        ret = iwl_sta_rx_agg_stop(priv, sta, tid);
        break;
    case IEEE80211_AMPDU_TX_START:
        if (!priv->trans->ops->txq_enable)
            break;
        if (iwlwifi_mod_params.disable_11n & IWL_DISABLE_HT_TXAGG)
            break;
        IWL_DEBUG_HT(priv, "start Tx\n");
        ret = iwlagn_tx_agg_start(priv, vif, sta, tid, ssn);
        break;
    case IEEE80211_AMPDU_TX_STOP:
        IWL_DEBUG_HT(priv, "stop Tx\n");
        ret = iwlagn_tx_agg_stop(priv, vif, sta, tid);
        if ((ret == 0) && (priv->agg_tids_count > 0)) {
            priv->agg_tids_count--;
            IWL_DEBUG_HT(priv, "priv->agg_tids_count = %u\n",
                     priv->agg_tids_count);
        }
        if (!priv->agg_tids_count &&
            priv->hw_params.use_rts_for_aggregation) {
            /*
             * switch off RTS/CTS if it was previously enabled
             */
            sta_priv->lq_sta.lq.general_params.flags &=
                ~LINK_QUAL_FLAGS_SET_STA_TLC_RTS_MSK;
            iwl_send_lq_cmd(priv, iwl_rxon_ctx_from_vif(vif),
                    &sta_priv->lq_sta.lq, CMD_ASYNC, false);
        }
        break;
    case IEEE80211_AMPDU_TX_OPERATIONAL:
        ret = iwlagn_tx_agg_oper(priv, vif, sta, tid, buf_size);
        break;
    }
    mutex_unlock(&priv->mutex);
    IWL_DEBUG_MAC80211(priv, "leave\n");
    return ret;
}

static int iwlagn_mac_sta_add(struct ieee80211_hw *hw,
                  struct ieee80211_vif *vif,
                  struct ieee80211_sta *sta)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    struct iwl_station_priv *sta_priv = (void *)sta->drv_priv;
    struct iwl_vif_priv *vif_priv = (void *)vif->drv_priv;
    bool is_ap = vif->type == NL80211_IFTYPE_STATION;
    int ret;
    u8 sta_id;

    IWL_DEBUG_INFO(priv, "proceeding to add station %pM\n",
            sta->addr);
    sta_priv->sta_id = IWL_INVALID_STATION;

    atomic_set(&sta_priv->pending_frames, 0);
    if (vif->type == NL80211_IFTYPE_AP)
        sta_priv->client = true;

    ret = iwl_add_station_common(priv, vif_priv->ctx, sta->addr,
                     is_ap, sta, &sta_id);
    if (ret) {
        IWL_ERR(priv, "Unable to add station %pM (%d)\n",
            sta->addr, ret);
        /* Should we return success if return code is EEXIST ? */
        return ret;
    }

    sta_priv->sta_id = sta_id;

    return 0;
}

static int iwlagn_mac_sta_remove(struct ieee80211_hw *hw,
                 struct ieee80211_vif *vif,
                 struct ieee80211_sta *sta)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    struct iwl_station_priv *sta_priv = (void *)sta->drv_priv;
    int ret;

    IWL_DEBUG_INFO(priv, "proceeding to remove station %pM\n", sta->addr);

    if (vif->type == NL80211_IFTYPE_STATION) {
        /*
         * Station will be removed from device when the RXON
         * is set to unassociated -- just deactivate it here
         * to avoid re-programming it.
         */
        ret = 0;
        iwl_deactivate_station(priv, sta_priv->sta_id, sta->addr);
    } else {
        ret = iwl_remove_station(priv, sta_priv->sta_id, sta->addr);
        if (ret)
            IWL_DEBUG_QUIET_RFKILL(priv,
                "Error removing station %pM\n", sta->addr);
    }
    return ret;
}

static int iwlagn_mac_sta_state(struct ieee80211_hw *hw,
                struct ieee80211_vif *vif,
                struct ieee80211_sta *sta,
                enum ieee80211_sta_state old_state,
                enum ieee80211_sta_state new_state)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    struct iwl_vif_priv *vif_priv = (void *)vif->drv_priv;
    enum {
        NONE, ADD, REMOVE, HT_RATE_INIT, ADD_RATE_INIT,
    } op = NONE;
    int ret;

    IWL_DEBUG_MAC80211(priv, "station %pM state change %d->%d\n",
               sta->addr, old_state, new_state);

    mutex_lock(&priv->mutex);
    if (vif->type == NL80211_IFTYPE_STATION) {
        if (old_state == IEEE80211_STA_NOTEXIST &&
            new_state == IEEE80211_STA_NONE)
            op = ADD;
        else if (old_state == IEEE80211_STA_NONE &&
             new_state == IEEE80211_STA_NOTEXIST)
            op = REMOVE;
        else if (old_state == IEEE80211_STA_AUTH &&
             new_state == IEEE80211_STA_ASSOC)
            op = HT_RATE_INIT;
    } else {
        if (old_state == IEEE80211_STA_AUTH &&
            new_state == IEEE80211_STA_ASSOC)
            op = ADD_RATE_INIT;
        else if (old_state == IEEE80211_STA_ASSOC &&
             new_state == IEEE80211_STA_AUTH)
            op = REMOVE;
    }

    switch (op) {
    case ADD:
        ret = iwlagn_mac_sta_add(hw, vif, sta);
        if (ret)
            break;
        /*
         * Clear the in-progress flag, the AP station entry was added
         * but we'll initialize LQ only when we've associated (which
         * would also clear the in-progress flag). This is necessary
         * in case we never initialize LQ because association fails.
         */
        spin_lock_bh(&priv->sta_lock);
        priv->stations[iwl_sta_id(sta)].used &=
            ~IWL_STA_UCODE_INPROGRESS;
        spin_unlock_bh(&priv->sta_lock);
        break;
    case REMOVE:
        ret = iwlagn_mac_sta_remove(hw, vif, sta);
        break;
    case ADD_RATE_INIT:
        ret = iwlagn_mac_sta_add(hw, vif, sta);
        if (ret)
            break;
        /* Initialize rate scaling */
        IWL_DEBUG_INFO(priv,
                   "Initializing rate scaling for station %pM\n",
                   sta->addr);
        iwl_rs_rate_init(priv, sta, iwl_sta_id(sta));
        ret = 0;
        break;
    case HT_RATE_INIT:
        /* Initialize rate scaling */
        ret = iwl_sta_update_ht(priv, vif_priv->ctx, sta);
        if (ret)
            break;
        IWL_DEBUG_INFO(priv,
                   "Initializing rate scaling for station %pM\n",
                   sta->addr);
        iwl_rs_rate_init(priv, sta, iwl_sta_id(sta));
        ret = 0;
        break;
    default:
        ret = 0;
        break;
    }

    /*
     * mac80211 might WARN if we fail, but due the way we
     * (badly) handle hard rfkill, we might fail here
     */
    if (iwl_is_rfkill(priv))
        ret = 0;

    mutex_unlock(&priv->mutex);
    IWL_DEBUG_MAC80211(priv, "leave\n");

    return ret;
}

static void iwlagn_mac_channel_switch(struct ieee80211_hw *hw,
                      struct ieee80211_channel_switch *ch_switch)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    struct ieee80211_conf *conf = &hw->conf;
    struct ieee80211_channel *channel = ch_switch->channel;
    struct iwl_ht_config *ht_conf = &priv->current_ht_config;
    /*
     * MULTI-FIXME
     * When we add support for multiple interfaces, we need to
     * revisit this. The channel switch command in the device
     * only affects the BSS context, but what does that really
     * mean? And what if we get a CSA on the second interface?
     * This needs a lot of work.
     */
    struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
    u16 ch;

    IWL_DEBUG_MAC80211(priv, "enter\n");

    mutex_lock(&priv->mutex);

    if (iwl_is_rfkill(priv))
        goto out;

    if (test_bit(STATUS_EXIT_PENDING, &priv->status) ||
        test_bit(STATUS_SCANNING, &priv->status) ||
        test_bit(STATUS_CHANNEL_SWITCH_PENDING, &priv->status))
        goto out;

    if (!iwl_is_associated_ctx(ctx))
        goto out;

    if (!priv->lib->set_channel_switch)
        goto out;

    ch = channel->hw_value;
    if (le16_to_cpu(ctx->active.channel) == ch)
        goto out;

    priv->current_ht_config.smps = conf->smps_mode;

    /* Configure HT40 channels */
    ctx->ht.enabled = conf_is_ht(conf);
    if (ctx->ht.enabled)
        iwlagn_config_ht40(conf, ctx);
    else
        ctx->ht.is_40mhz = false;

    if ((le16_to_cpu(ctx->staging.channel) != ch))
        ctx->staging.flags = 0;

    iwl_set_rxon_channel(priv, channel, ctx);
    iwl_set_rxon_ht(priv, ht_conf);
    iwl_set_flags_for_band(priv, ctx, channel->band, ctx->vif);

    /*
     * at this point, staging_rxon has the
     * configuration for channel switch
     */
    set_bit(STATUS_CHANNEL_SWITCH_PENDING, &priv->status);
    priv->switch_channel = cpu_to_le16(ch);
    if (priv->lib->set_channel_switch(priv, ch_switch)) {
        clear_bit(STATUS_CHANNEL_SWITCH_PENDING, &priv->status);
        priv->switch_channel = 0;
        ieee80211_chswitch_done(ctx->vif, false);
    }

out:
    mutex_unlock(&priv->mutex);
    IWL_DEBUG_MAC80211(priv, "leave\n");
}

void iwl_chswitch_done(struct iwl_priv *priv, bool is_success)
{
    /*
     * MULTI-FIXME
     * See iwlagn_mac_channel_switch.
     */
    struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];

    if (test_bit(STATUS_EXIT_PENDING, &priv->status))
        return;

    if (test_and_clear_bit(STATUS_CHANNEL_SWITCH_PENDING, &priv->status))
        ieee80211_chswitch_done(ctx->vif, is_success);
}

static void iwlagn_configure_filter(struct ieee80211_hw *hw,
                    unsigned int changed_flags,
                    unsigned int *total_flags,
                    u64 multicast)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    __le32 filter_or = 0, filter_nand = 0;
    struct iwl_rxon_context *ctx;

#define CHK(test, flag) do { \
    if (*total_flags & (test))      \
        filter_or |= (flag);        \
    else                    \
        filter_nand |= (flag);      \
    } while (0)

    IWL_DEBUG_MAC80211(priv, "Enter: changed: 0x%x, total: 0x%x\n",
            changed_flags, *total_flags);

    CHK(FIF_OTHER_BSS | FIF_PROMISC_IN_BSS, RXON_FILTER_PROMISC_MSK);
    /* Setting _just_ RXON_FILTER_CTL2HOST_MSK causes FH errors */
    CHK(FIF_CONTROL, RXON_FILTER_CTL2HOST_MSK | RXON_FILTER_PROMISC_MSK);
    CHK(FIF_BCN_PRBRESP_PROMISC, RXON_FILTER_BCON_AWARE_MSK);

#undef CHK

    mutex_lock(&priv->mutex);

    for_each_context(priv, ctx) {
        ctx->staging.filter_flags &= ~filter_nand;
        ctx->staging.filter_flags |= filter_or;

        /*
         * Not committing directly because hardware can perform a scan,
         * but we'll eventually commit the filter flags change anyway.
         */
    }

    mutex_unlock(&priv->mutex);

    /*
     * Receiving all multicast frames is always enabled by the
     * default flags setup in iwl_connection_init_rx_config()
     * since we currently do not support programming multicast
     * filters into the device.
     */
    *total_flags &= FIF_OTHER_BSS | FIF_ALLMULTI | FIF_PROMISC_IN_BSS |
            FIF_BCN_PRBRESP_PROMISC | FIF_CONTROL;
}

static void iwlagn_mac_flush(struct ieee80211_hw *hw, bool drop)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);

    mutex_lock(&priv->mutex);
    IWL_DEBUG_MAC80211(priv, "enter\n");

    if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
        IWL_DEBUG_TX(priv, "Aborting flush due to device shutdown\n");
        goto done;
    }
    if (iwl_is_rfkill(priv)) {
        IWL_DEBUG_TX(priv, "Aborting flush due to RF Kill\n");
        goto done;
    }

    /*
     * mac80211 will not push any more frames for transmit
     * until the flush is completed
     */
    if (drop) {
        IWL_DEBUG_MAC80211(priv, "send flush command\n");
        if (iwlagn_txfifo_flush(priv, IWL_DROP_ALL)) {
            IWL_ERR(priv, "flush request fail\n");
            goto done;
        }
    }
    IWL_DEBUG_MAC80211(priv, "wait transmit/flush all frames\n");
    iwl_trans_wait_tx_queue_empty(priv->trans);
done:
    mutex_unlock(&priv->mutex);
    IWL_DEBUG_MAC80211(priv, "leave\n");
}

static int iwlagn_mac_remain_on_channel(struct ieee80211_hw *hw,
                     struct ieee80211_channel *channel,
                     enum nl80211_channel_type channel_type,
                     int duration)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_PAN];
    int err = 0;

    if (!(priv->valid_contexts & BIT(IWL_RXON_CTX_PAN)))
        return -EOPNOTSUPP;

    if (!(ctx->interface_modes & BIT(NL80211_IFTYPE_P2P_CLIENT)))
        return -EOPNOTSUPP;

    IWL_DEBUG_MAC80211(priv, "enter\n");
    mutex_lock(&priv->mutex);

    if (test_bit(STATUS_SCAN_HW, &priv->status)) {
        /* mac80211 should not scan while ROC or ROC while scanning */
        if (WARN_ON_ONCE(priv->scan_type != IWL_SCAN_RADIO_RESET)) {
            err = -EBUSY;
            goto out;
        }

        iwl_scan_cancel_timeout(priv, 100);

        if (test_bit(STATUS_SCAN_HW, &priv->status)) {
            err = -EBUSY;
            goto out;
        }
    }

    priv->hw_roc_channel = channel;
    priv->hw_roc_chantype = channel_type;
    /* convert from ms to TU */
    priv->hw_roc_duration = DIV_ROUND_UP(1000 * duration, 1024);
    priv->hw_roc_start_notified = false;
    cancel_delayed_work(&priv->hw_roc_disable_work);

    if (!ctx->is_active) {
        static const struct iwl_qos_info default_qos_data = {
            .def_qos_parm = {
                .ac[0] = {
                    .cw_min = cpu_to_le16(3),
                    .cw_max = cpu_to_le16(7),
                    .aifsn = 2,
                    .edca_txop = cpu_to_le16(1504),
                },
                .ac[1] = {
                    .cw_min = cpu_to_le16(7),
                    .cw_max = cpu_to_le16(15),
                    .aifsn = 2,
                    .edca_txop = cpu_to_le16(3008),
                },
                .ac[2] = {
                    .cw_min = cpu_to_le16(15),
                    .cw_max = cpu_to_le16(1023),
                    .aifsn = 3,
                },
                .ac[3] = {
                    .cw_min = cpu_to_le16(15),
                    .cw_max = cpu_to_le16(1023),
                    .aifsn = 7,
                },
            },
        };

        ctx->is_active = true;
        ctx->qos_data = default_qos_data;
        ctx->staging.dev_type = RXON_DEV_TYPE_P2P;
        memcpy(ctx->staging.node_addr,
               priv->contexts[IWL_RXON_CTX_BSS].staging.node_addr,
               ETH_ALEN);
        memcpy(ctx->staging.bssid_addr,
               priv->contexts[IWL_RXON_CTX_BSS].staging.node_addr,
               ETH_ALEN);
        err = iwlagn_commit_rxon(priv, ctx);
        if (err)
            goto out;
        ctx->staging.filter_flags |= RXON_FILTER_ASSOC_MSK |
                         RXON_FILTER_PROMISC_MSK |
                         RXON_FILTER_CTL2HOST_MSK;

        err = iwlagn_commit_rxon(priv, ctx);
        if (err) {
            iwlagn_disable_roc(priv);
            goto out;
        }
        priv->hw_roc_setup = true;
    }

    err = iwl_scan_initiate(priv, ctx->vif, IWL_SCAN_ROC, channel->band);
    if (err)
        iwlagn_disable_roc(priv);

 out:
    mutex_unlock(&priv->mutex);
    IWL_DEBUG_MAC80211(priv, "leave\n");

    return err;
}

static int iwlagn_mac_cancel_remain_on_channel(struct ieee80211_hw *hw)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);

    if (!(priv->valid_contexts & BIT(IWL_RXON_CTX_PAN)))
        return -EOPNOTSUPP;

    IWL_DEBUG_MAC80211(priv, "enter\n");
    mutex_lock(&priv->mutex);
    iwl_scan_cancel_timeout(priv, priv->hw_roc_duration);
    iwlagn_disable_roc(priv);
    mutex_unlock(&priv->mutex);
    IWL_DEBUG_MAC80211(priv, "leave\n");

    return 0;
}

static void iwlagn_mac_rssi_callback(struct ieee80211_hw *hw,
                     enum ieee80211_rssi_event rssi_event)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);

    IWL_DEBUG_MAC80211(priv, "enter\n");
    mutex_lock(&priv->mutex);

    if (priv->cfg->bt_params &&
            priv->cfg->bt_params->advanced_bt_coexist) {
        if (rssi_event == RSSI_EVENT_LOW)
            priv->bt_enable_pspoll = true;
        else if (rssi_event == RSSI_EVENT_HIGH)
            priv->bt_enable_pspoll = false;

        iwlagn_send_advance_bt_config(priv);
    } else {
        IWL_DEBUG_MAC80211(priv, "Advanced BT coex disabled,"
                "ignoring RSSI callback\n");
    }

    mutex_unlock(&priv->mutex);
    IWL_DEBUG_MAC80211(priv, "leave\n");
}

static int iwlagn_mac_set_tim(struct ieee80211_hw *hw,
                  struct ieee80211_sta *sta, bool set)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);

    queue_work(priv->workqueue, &priv->beacon_update);

    return 0;
}

static int iwlagn_mac_conf_tx(struct ieee80211_hw *hw,
                  struct ieee80211_vif *vif, u16 queue,
                  const struct ieee80211_tx_queue_params *params)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    struct iwl_vif_priv *vif_priv = (void *)vif->drv_priv;
    struct iwl_rxon_context *ctx = vif_priv->ctx;
    int q;

    if (WARN_ON(!ctx))
        return -EINVAL;

    IWL_DEBUG_MAC80211(priv, "enter\n");

    if (!iwl_is_ready_rf(priv)) {
        IWL_DEBUG_MAC80211(priv, "leave - RF not ready\n");
        return -EIO;
    }

    if (queue >= AC_NUM) {
        IWL_DEBUG_MAC80211(priv, "leave - queue >= AC_NUM %d\n", queue);
        return 0;
    }

    q = AC_NUM - 1 - queue;

    mutex_lock(&priv->mutex);

    ctx->qos_data.def_qos_parm.ac[q].cw_min =
        cpu_to_le16(params->cw_min);
    ctx->qos_data.def_qos_parm.ac[q].cw_max =
        cpu_to_le16(params->cw_max);
    ctx->qos_data.def_qos_parm.ac[q].aifsn = params->aifs;
    ctx->qos_data.def_qos_parm.ac[q].edca_txop =
            cpu_to_le16((params->txop * 32));

    ctx->qos_data.def_qos_parm.ac[q].reserved1 = 0;

    mutex_unlock(&priv->mutex);

    IWL_DEBUG_MAC80211(priv, "leave\n");
    return 0;
}

static int iwlagn_mac_tx_last_beacon(struct ieee80211_hw *hw)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);

    return priv->ibss_manager == IWL_IBSS_MANAGER;
}

static int iwl_set_mode(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
{
    iwl_connection_init_rx_config(priv, ctx);

    iwlagn_set_rxon_chain(priv, ctx);

    return iwlagn_commit_rxon(priv, ctx);
}

static int iwl_setup_interface(struct iwl_priv *priv,
                   struct iwl_rxon_context *ctx)
{
    struct ieee80211_vif *vif = ctx->vif;
    int err, ac;

    lockdep_assert_held(&priv->mutex);

    /*
     * This variable will be correct only when there's just
     * a single context, but all code using it is for hardware
     * that supports only one context.
     */
    priv->iw_mode = vif->type;

    ctx->is_active = true;

    err = iwl_set_mode(priv, ctx);
    if (err) {
        if (!ctx->always_active)
            ctx->is_active = false;
        return err;
    }

    if (priv->cfg->bt_params && priv->cfg->bt_params->advanced_bt_coexist &&
        vif->type == NL80211_IFTYPE_ADHOC) {
        /*
         * pretend to have high BT traffic as long as we
         * are operating in IBSS mode, as this will cause
         * the rate scaling etc. to behave as intended.
         */
        priv->bt_traffic_load = IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
    }

    /* set up queue mappings */
    for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
        vif->hw_queue[ac] = ctx->ac_to_queue[ac];

    if (vif->type == NL80211_IFTYPE_AP)
        vif->cab_queue = ctx->mcast_queue;
    else
        vif->cab_queue = IEEE80211_INVAL_HW_QUEUE;

    return 0;
}

static int iwlagn_mac_add_interface(struct ieee80211_hw *hw,
                    struct ieee80211_vif *vif)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    struct iwl_vif_priv *vif_priv = (void *)vif->drv_priv;
    struct iwl_rxon_context *tmp, *ctx = NULL;
    int err;
    enum nl80211_iftype viftype = ieee80211_vif_type_p2p(vif);
    bool reset = false;

    IWL_DEBUG_MAC80211(priv, "enter: type %d, addr %pM\n",
               viftype, vif->addr);

    cancel_delayed_work_sync(&priv->hw_roc_disable_work);

    mutex_lock(&priv->mutex);

    iwlagn_disable_roc(priv);

    if (!iwl_is_ready_rf(priv)) {
        IWL_WARN(priv, "Try to add interface when device not ready\n");
        err = -EINVAL;
        goto out;
    }

    for_each_context(priv, tmp) {
        u32 possible_modes =
            tmp->interface_modes | tmp->exclusive_interface_modes;

        if (tmp->vif) {
            /* On reset we need to add the same interface again */
            if (tmp->vif == vif) {
                reset = true;
                ctx = tmp;
                break;
            }

            /* check if this busy context is exclusive */
            if (tmp->exclusive_interface_modes &
                        BIT(tmp->vif->type)) {
                err = -EINVAL;
                goto out;
            }
            continue;
        }

        if (!(possible_modes & BIT(viftype)))
            continue;

        /* have maybe usable context w/o interface */
        ctx = tmp;
        break;
    }

    if (!ctx) {
        err = -EOPNOTSUPP;
        goto out;
    }

    vif_priv->ctx = ctx;
    ctx->vif = vif;

    /*
     * In SNIFFER device type, the firmware reports the FCS to
     * the host, rather than snipping it off. Unfortunately,
     * mac80211 doesn't (yet) provide a per-packet flag for
     * this, so that we have to set the hardware flag based
     * on the interfaces added. As the monitor interface can
     * only be present by itself, and will be removed before
     * other interfaces are added, this is safe.
     */
    if (vif->type == NL80211_IFTYPE_MONITOR)
        priv->hw->flags |= IEEE80211_HW_RX_INCLUDES_FCS;
    else
        priv->hw->flags &= ~IEEE80211_HW_RX_INCLUDES_FCS;

    err = iwl_setup_interface(priv, ctx);
    if (!err || reset)
        goto out;

    ctx->vif = NULL;
    priv->iw_mode = NL80211_IFTYPE_STATION;
 out:
    mutex_unlock(&priv->mutex);

    IWL_DEBUG_MAC80211(priv, "leave\n");
    return err;
}

static void iwl_teardown_interface(struct iwl_priv *priv,
                   struct ieee80211_vif *vif,
                   bool mode_change)
{
    struct iwl_rxon_context *ctx = iwl_rxon_ctx_from_vif(vif);

    lockdep_assert_held(&priv->mutex);

    if (priv->scan_vif == vif) {
        iwl_scan_cancel_timeout(priv, 200);
        iwl_force_scan_end(priv);
    }

    if (!mode_change) {
        iwl_set_mode(priv, ctx);
        if (!ctx->always_active)
            ctx->is_active = false;
    }

    /*
     * When removing the IBSS interface, overwrite the
     * BT traffic load with the stored one from the last
     * notification, if any. If this is a device that
     * doesn't implement this, this has no effect since
     * both values are the same and zero.
     */
    if (vif->type == NL80211_IFTYPE_ADHOC)
        priv->bt_traffic_load = priv->last_bt_traffic_load;
}

static void iwlagn_mac_remove_interface(struct ieee80211_hw *hw,
                  struct ieee80211_vif *vif)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    struct iwl_rxon_context *ctx = iwl_rxon_ctx_from_vif(vif);

    IWL_DEBUG_MAC80211(priv, "enter\n");

    mutex_lock(&priv->mutex);

    if (WARN_ON(ctx->vif != vif)) {
        struct iwl_rxon_context *tmp;
        IWL_ERR(priv, "ctx->vif = %p, vif = %p\n", ctx->vif, vif);
        for_each_context(priv, tmp)
            IWL_ERR(priv, "\tID = %d:\tctx = %p\tctx->vif = %p\n",
                tmp->ctxid, tmp, tmp->vif);
    }
    ctx->vif = NULL;

    iwl_teardown_interface(priv, vif, false);

    mutex_unlock(&priv->mutex);

    IWL_DEBUG_MAC80211(priv, "leave\n");

}

static int iwlagn_mac_change_interface(struct ieee80211_hw *hw,
                       struct ieee80211_vif *vif,
                       enum nl80211_iftype newtype, bool newp2p)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    struct iwl_rxon_context *ctx, *tmp;
    enum nl80211_iftype newviftype = newtype;
    u32 interface_modes;
    int err;

    IWL_DEBUG_MAC80211(priv, "enter\n");

    newtype = ieee80211_iftype_p2p(newtype, newp2p);

    mutex_lock(&priv->mutex);

    ctx = iwl_rxon_ctx_from_vif(vif);

    /*
     * To simplify this code, only support changes on the
     * BSS context. The PAN context is usually reassigned
     * by creating/removing P2P interfaces anyway.
     */
    if (ctx->ctxid != IWL_RXON_CTX_BSS) {
        err = -EBUSY;
        goto out;
    }

    if (!ctx->vif || !iwl_is_ready_rf(priv)) {
        /*
         * Huh? But wait ... this can maybe happen when
         * we're in the middle of a firmware restart!
         */
        err = -EBUSY;
        goto out;
    }

    /* Check if the switch is supported in the same context */
    interface_modes = ctx->interface_modes | ctx->exclusive_interface_modes;
    if (!(interface_modes & BIT(newtype))) {
        err = -EBUSY;
        goto out;
    }

    if (ctx->exclusive_interface_modes & BIT(newtype)) {
        for_each_context(priv, tmp) {
            if (ctx == tmp)
                continue;

            if (!tmp->is_active)
                continue;

            /*
             * The current mode switch would be exclusive, but
             * another context is active ... refuse the switch.
             */
            err = -EBUSY;
            goto out;
        }
    }

    /* success */
    iwl_teardown_interface(priv, vif, true);
    vif->type = newviftype;
    vif->p2p = newp2p;
    err = iwl_setup_interface(priv, ctx);
    WARN_ON(err);
    /*
     * We've switched internally, but submitting to the
     * device may have failed for some reason. Mask this
     * error, because otherwise mac80211 will not switch
     * (and set the interface type back) and we'll be
     * out of sync with it.
     */
    err = 0;

 out:
    mutex_unlock(&priv->mutex);
    IWL_DEBUG_MAC80211(priv, "leave\n");

    return err;
}

static int iwlagn_mac_hw_scan(struct ieee80211_hw *hw,
                  struct ieee80211_vif *vif,
                  struct cfg80211_scan_request *req)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    int ret;

    IWL_DEBUG_MAC80211(priv, "enter\n");

    if (req->n_channels == 0)
        return -EINVAL;

    mutex_lock(&priv->mutex);

    /*
     * If an internal scan is in progress, just set
     * up the scan_request as per above.
     */
    if (priv->scan_type != IWL_SCAN_NORMAL) {
        IWL_DEBUG_SCAN(priv,
                   "SCAN request during internal scan - defer\n");
        priv->scan_request = req;
        priv->scan_vif = vif;
        ret = 0;
    } else {
        priv->scan_request = req;
        priv->scan_vif = vif;
        /*
         * mac80211 will only ask for one band at a time
         * so using channels[0] here is ok
         */
        ret = iwl_scan_initiate(priv, vif, IWL_SCAN_NORMAL,
                    req->channels[0]->band);
        if (ret) {
            priv->scan_request = NULL;
            priv->scan_vif = NULL;
        }
    }

    IWL_DEBUG_MAC80211(priv, "leave\n");

    mutex_unlock(&priv->mutex);

    return ret;
}

static void iwl_sta_modify_ps_wake(struct iwl_priv *priv, int sta_id)
{
    struct iwl_addsta_cmd cmd = {
        .mode = STA_CONTROL_MODIFY_MSK,
        .station_flags_msk = STA_FLG_PWR_SAVE_MSK,
        .sta.sta_id = sta_id,
    };

    iwl_send_add_sta(priv, &cmd, CMD_ASYNC);
}

static void iwlagn_mac_sta_notify(struct ieee80211_hw *hw,
                  struct ieee80211_vif *vif,
                  enum sta_notify_cmd cmd,
                  struct ieee80211_sta *sta)
{
    struct iwl_priv *priv = IWL_MAC80211_GET_DVM(hw);
    struct iwl_station_priv *sta_priv = (void *)sta->drv_priv;
    int sta_id;

    IWL_DEBUG_MAC80211(priv, "enter\n");

    switch (cmd) {
    case STA_NOTIFY_SLEEP:
        WARN_ON(!sta_priv->client);
        sta_priv->asleep = true;
        if (atomic_read(&sta_priv->pending_frames) > 0)
            ieee80211_sta_block_awake(hw, sta, true);
        break;
    case STA_NOTIFY_AWAKE:
        WARN_ON(!sta_priv->client);
        if (!sta_priv->asleep)
            break;
        sta_priv->asleep = false;
        sta_id = iwl_sta_id(sta);
        if (sta_id != IWL_INVALID_STATION)
            iwl_sta_modify_ps_wake(priv, sta_id);
        break;
    default:
        break;
    }
    IWL_DEBUG_MAC80211(priv, "leave\n");
}

struct ieee80211_ops iwlagn_hw_ops = {
    .tx = iwlagn_mac_tx,
    .start = iwlagn_mac_start,
    .stop = iwlagn_mac_stop,
#ifdef CONFIG_PM_SLEEP
    .suspend = iwlagn_mac_suspend,
    .resume = iwlagn_mac_resume,
    .set_wakeup = iwlagn_mac_set_wakeup,
#endif
    .add_interface = iwlagn_mac_add_interface,
    .remove_interface = iwlagn_mac_remove_interface,
    .change_interface = iwlagn_mac_change_interface,
    .config = iwlagn_mac_config,
    .configure_filter = iwlagn_configure_filter,
    .set_key = iwlagn_mac_set_key,
    .update_tkip_key = iwlagn_mac_update_tkip_key,
    .set_rekey_data = iwlagn_mac_set_rekey_data,
    .conf_tx = iwlagn_mac_conf_tx,
    .bss_info_changed = iwlagn_bss_info_changed,
    .ampdu_action = iwlagn_mac_ampdu_action,
    .hw_scan = iwlagn_mac_hw_scan,
    .sta_notify = iwlagn_mac_sta_notify,
    .sta_state = iwlagn_mac_sta_state,
    .channel_switch = iwlagn_mac_channel_switch,
    .flush = iwlagn_mac_flush,
    .tx_last_beacon = iwlagn_mac_tx_last_beacon,
    .remain_on_channel = iwlagn_mac_remain_on_channel,
    .cancel_remain_on_channel = iwlagn_mac_cancel_remain_on_channel,
    .rssi_callback = iwlagn_mac_rssi_callback,
    CFG80211_TESTMODE_CMD(iwlagn_mac_testmode_cmd)
    CFG80211_TESTMODE_DUMP(iwlagn_mac_testmode_dump)
    .set_tim = iwlagn_mac_set_tim,
};

/* This function both allocates and initializes hw and priv. */
struct ieee80211_hw *iwl_alloc_all(void)
{
    struct iwl_priv *priv;
    struct iwl_op_mode *op_mode;
    /* mac80211 allocates memory for this device instance, including
     *   space for this driver's private structure */
    struct ieee80211_hw *hw;

    hw = ieee80211_alloc_hw(sizeof(struct iwl_priv) +
                sizeof(struct iwl_op_mode), &iwlagn_hw_ops);
    if (!hw)
        goto out;

    op_mode = hw->priv;
    priv = IWL_OP_MODE_GET_DVM(op_mode);
    priv->hw = hw;

out:
    return hw;
}